New research indicates that inadequate water intake significantly elevates stress-related cortisol levels, highlighting the importance of hydration in stress management for both men and women.
A recent study conducted by researchers at Liverpool John Moores University (LJMU) emphasizes the critical role of hydration in managing stress. The findings reveal that individuals who consume less than seven cups, or approximately 1.5 liters, of water daily exhibit a cortisol response to stress that is 50% higher than those who adhere to recommended water intake levels.
The study, published in the Journal of Applied Physiology, involved 62 healthy participants, both male and female. Researchers categorized the subjects into two groups based on their fluid intake habits. The “low-fluid” group consisted of 32 individuals who typically drank less than 1.5 liters of fluid per day, while the “high-fluid” group included those who met the recommended daily intake of two liters for women and 2.5 liters for men.
Over a week, the participants’ fluid intake was monitored, and their responses were assessed using the Trier Social Stress Test (TSST) alongside hydration markers derived from blood and urine tests. The results indicated that insufficient water consumption exacerbated stress-related health issues for both genders.
Professor Neil Walsh, the study’s lead at LJMU’s School of Sport and Exercise Sciences, noted in a press release that keeping a water bottle accessible during stressful periods could offer significant long-term health benefits.
“Cortisol is the body’s primary stress hormone, and an exaggerated cortisol response to stress is linked to an increased risk of heart disease, diabetes, and depression,” Walsh explained.
Dr. Daniel Kashi, a member of the research team, added that both groups reported similar levels of anxiety and experienced comparable increases in heart rate during the stress test. However, only the low-fluid group exhibited a significant rise in saliva cortisol in response to the stressor.
“Interestingly, the low-fluid group did not report feeling thirstier than their high-fluid counterparts, yet their urine was darker and more concentrated—clear indicators of inadequate hydration,” Kashi remarked. “A crucial observation was that poor hydration correlated with heightened cortisol reactivity during the stress test. This exaggerated cortisol response has been associated with adverse long-term health outcomes.”
Long-term dehydration can lead to serious health complications, including kidney damage, anxiety, depression, heart issues, and diabetes, as noted by the Cleveland Clinic. Dehydration triggers the release of vasopressin, a hormone that places additional strain on the kidneys, complicating urine concentration and electrolyte balance.
According to the LJMU release, “Vasopressin also influences the brain’s stress-response center, affecting cortisol release.” This dual role of vasopressin helps maintain blood volume and electrolyte balance while simultaneously increasing cortisol levels.
While the study underscores the necessity of adhering to water intake recommendations, researchers advocate for further investigations and long-term studies to deepen understanding of hydration’s impact on stress management.
To monitor hydration status, researchers suggest observing urine color, with light yellow typically indicating adequate hydration. “Being hydrated may help your body manage stress more effectively,” Walsh concluded.
Source: Original article